emerged in 1917 and deepened in 1919. Following the 1917, Bolshevik revolution in Russia, Russian communists turned against socialists imprisoning them and sometimes torturing and killing them. SPD feared a communist revolution in Germany would lead to the KPD persecuting the SPD. 1919 - the SPD authorised military actions against KPD rebels in Germany's major cities. The relationship between SPD and KPD deteriorated, meaning that the 2 parties could not work together.